Multiphase equation of state for carbon addressing high pressures and temperatures
We present a 5-phase equation of state for elemental carbon which addresses a wide range of density and temperature conditions: 3g/cc < ρ < 20g/cc, 0K < T < ∞. The phases considered are diamond, BC8, simple cubic, simple hexagonal, and the liquid/plasma state. The solid phase free energi...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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American Physical Society
2014
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| Online Access: | http://hdl.handle.net/1721.1/88642 |
| _version_ | 1826215039883804672 |
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| author | Benedict, Lorin X. Driver, Kevin P. Hamel, Sebastien Militzer, Burkhard Qi, Tingting Correa, Alfredo A. Schwegler, Eric Saul, Alberto Andres |
| author2 | Massachusetts Institute of Technology. Department of Civil and Environmental Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Benedict, Lorin X. Driver, Kevin P. Hamel, Sebastien Militzer, Burkhard Qi, Tingting Correa, Alfredo A. Schwegler, Eric Saul, Alberto Andres |
| author_sort | Benedict, Lorin X. |
| collection | MIT |
| description | We present a 5-phase equation of state for elemental carbon which addresses a wide range of density and temperature conditions: 3g/cc < ρ < 20g/cc, 0K < T < ∞. The phases considered are diamond, BC8, simple cubic, simple hexagonal, and the liquid/plasma state. The solid phase free energies are constrained by density functional theory (DFT) calculations. Vibrational contributions to the free energy of each solid phase are treated within the quasiharmonic framework. The liquid free energy model is constrained by fitting to a combination of DFT molecular dynamics performed over the range 10 000K < T < 100 000K, and path integral quantum Monte Carlo calculations for T > 100 000K (both for ρ between 3 and 12 g/cc, with select higher-ρ DFT calculations as well). The liquid free energy model includes an atom-in-jellium approach to account for the effects of ionization due to temperature and pressure in the plasma state, and an ion-thermal model which includes the approach to the ideal gas limit. The precise manner in which the ideal gas limit is reached is greatly constrained by both the highest-temperature DFT data and the path integral data, forcing us to discard an ion-thermal model we had used previously in favor of a new one. Predictions are made for the principal Hugoniot and the room-temperature isotherm, and comparisons are made to recent experimental results. |
| first_indexed | 2024-09-23T16:15:33Z |
| format | Article |
| id | mit-1721.1/88642 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T16:15:33Z |
| publishDate | 2014 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/886422022-10-02T07:19:53Z Multiphase equation of state for carbon addressing high pressures and temperatures Benedict, Lorin X. Driver, Kevin P. Hamel, Sebastien Militzer, Burkhard Qi, Tingting Correa, Alfredo A. Schwegler, Eric Saul, Alberto Andres Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Saul, Alberto Andres We present a 5-phase equation of state for elemental carbon which addresses a wide range of density and temperature conditions: 3g/cc < ρ < 20g/cc, 0K < T < ∞. The phases considered are diamond, BC8, simple cubic, simple hexagonal, and the liquid/plasma state. The solid phase free energies are constrained by density functional theory (DFT) calculations. Vibrational contributions to the free energy of each solid phase are treated within the quasiharmonic framework. The liquid free energy model is constrained by fitting to a combination of DFT molecular dynamics performed over the range 10 000K < T < 100 000K, and path integral quantum Monte Carlo calculations for T > 100 000K (both for ρ between 3 and 12 g/cc, with select higher-ρ DFT calculations as well). The liquid free energy model includes an atom-in-jellium approach to account for the effects of ionization due to temperature and pressure in the plasma state, and an ion-thermal model which includes the approach to the ideal gas limit. The precise manner in which the ideal gas limit is reached is greatly constrained by both the highest-temperature DFT data and the path integral data, forcing us to discard an ion-thermal model we had used previously in favor of a new one. Predictions are made for the principal Hugoniot and the room-temperature isotherm, and comparisons are made to recent experimental results. United States. Dept. of Energy (Contract DE-AC52-07NA27344) 2014-08-08T19:08:32Z 2014-08-08T19:08:32Z 2014-06 2014-05 2014-07-23T20:47:27Z Article http://purl.org/eprint/type/JournalArticle 1098-0121 1550-235X http://hdl.handle.net/1721.1/88642 Benedict, Lorin X., Kevin P. Driver, Sebastien Hamel, Burkhard Militzer, Tingting Qi, Alfredo A. Correa, A. Saul, and Eric Schwegler. “Multiphase Equation of State for Carbon Addressing High Pressures and Temperatures.” Phys. Rev. B 89, no. 22 (June 2014). © 2014 American Physical Society en http://dx.doi.org/10.1103/PhysRevB.89.224109 Physical Review B Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. American Physical Society application/pdf American Physical Society American Physical Society |
| spellingShingle | Benedict, Lorin X. Driver, Kevin P. Hamel, Sebastien Militzer, Burkhard Qi, Tingting Correa, Alfredo A. Schwegler, Eric Saul, Alberto Andres Multiphase equation of state for carbon addressing high pressures and temperatures |
| title | Multiphase equation of state for carbon addressing high pressures and temperatures |
| title_full | Multiphase equation of state for carbon addressing high pressures and temperatures |
| title_fullStr | Multiphase equation of state for carbon addressing high pressures and temperatures |
| title_full_unstemmed | Multiphase equation of state for carbon addressing high pressures and temperatures |
| title_short | Multiphase equation of state for carbon addressing high pressures and temperatures |
| title_sort | multiphase equation of state for carbon addressing high pressures and temperatures |
| url | http://hdl.handle.net/1721.1/88642 |
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